This invention relates to improved cured foam rubber compositions.
Microcellular vulcanized rubber is conventionally fabricated in two steps. The first step (precure) consists of the compression molding of the compound at a temperature high enough to vulcanize the rubber and decompose the blowing agent. After the first cure, the microcellular product continues to slowly shrink at room temperature. Thus, a second step (postcure or stabilization) is necessary to stabilize the product. This may be done by a second compression molding at the same temperature as the first one or more generally by heating in an air oven at 70.degree. to 130.degree. C. (for example, 1 hour at 130.degree. C., 2 hours at 100.degree. C., or 4 hours at 70.degree. C.).